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N-heptane
Heptane or ''n''-heptane is the straight-chain alkane with the chemical formula H3C(CH2)5CH3 or C7H16. When used as a test fuel component in anti-knock test engines, a 100% heptane fuel is the zero point of the octane rating scale (the 100 point is 100% iso-octane). Octane number equates to the anti-knock qualities of a comparison mixture of heptane and isooctane which is expressed as the percentage of isooctane in heptane and is listed on pumps for gasoline (petrol) dispensed globally. Uses Heptane (and its many isomers) is widely used in laboratories as a non-polar solvent. As a liquid, it is ideal for transport and storage. In the grease spot test, heptane is used to dissolve an oil spot to show the previous presence of organic compounds on a stained paper. This is done by shaking the stained paper in a heptane solution for about half a minute. Aqueous bromine may be distinguished from aqueous iodine by its appearance after extraction into heptane. In water, both bromine a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jeffrey Pine
''Pinus jeffreyi'', also known as Jeffrey pine, Jeffrey's pine, yellow pine and black pine, is a North American pine tree. It is mainly found in California, but also in the westernmost part of Nevada, southwestern Oregon, and northern Baja California.Safford, H.D. 2013. Natural Range of Variation (NRV) for yellow pine and mixed conifer forests in the bioregional assessment area, including the Sierra Nevada, southern Cascades, and Modoc and Inyo National Forests. Unpublished report. USDA Forest Service, Pacific Southwest Region, Vallejo, CA/ref> It is named in honor of its botanist documenter John Jeffrey (botanist), John Jeffrey. Description ''Pinus jeffreyi'' is a large coniferous evergreen tree, reaching tall, rarely up to tall, though smaller when growing at or near tree line. The leaves are needle-like, in bundles of three, stout, glaucous gray-green, long. The cones are long, dark purple when immature, ripening pale brown, with thinly woody scales bearing a short, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rubber Cement
Rubber cement (cow gum in British English) is an adhesive made from elastic polymers (typically latex) mixed in a solvent such as acetone, hexane, heptane or toluene to keep it fluid enough to be used. This makes it part of the class of drying adhesives: as the solvents quickly evaporate, the rubber solidifies, forming a strong yet flexible bond. Composition Rubber cement is simply a mixture of solid rubber in a volatile solvent that will dissolve it. When the cement is applied, the solvent evaporates, leaving the rubber as the adhesive. Almost any rubber (pre- vulcanized or not) can be used. The rubbers used might be natural rubber, gum mastic or gum arabic. Early solvents used included chloroform and benzene. A small percentage of alcohol is often added to the mix. In the United States, current formulations include n-heptane. In the United Kingdom, a product called Marabu-Fixogum uses acetone, while a product called Copydex uses ammonia. Many special compositions includ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Octane Rating
An octane rating, or octane number, is a standard measure of a Liquid fuel, fuel's ability to withstand Compression ratio, compression in an internal combustion engine without Engine knocking, detonating. The higher the octane number, the more compression the fuel can withstand before detonating. Octane rating does not relate directly to the power output or the energy content of the fuel per unit mass or volume, but simply indicates gasoline's capability against compression. Whether or not a higher octane fuel improves or impairs an engine's performance depends on the design of the engine. In broad terms, fuels with a higher octane rating are used in higher-compression Petrol engine, gasoline engines, which may yield higher power for these engines. Such higher power comes from the fuel's higher compression by the engine design, and not directly from the gasoline. In contrast, fuels with lower octane (but higher cetane numbers) are ideal for diesel engines because diesel engines (al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexane
Hexane () is an organic compound, a straight-chain alkane with six carbon atoms and has the molecular formula C6H14. It is a colorless liquid, odorless when pure, and with boiling points approximately . It is widely used as a cheap, relatively safe, largely unreactive, and easily evaporated non-polar solvent, and modern gasoline blends contain about 3% hexane. The term ''hexanes'' refers to a mixture, composed largely (>60%) of hexane, with varying amounts of the isomeric compounds 2-methylpentane and 3-methylpentane, and, possibly, smaller amounts of nonisomeric C5, C6, and C7 (cyclo)alkanes. These ''hexanes'' are cheaper than pure hexane and are often used in large-scale operations not requiring a single isomer (e.g., as cleaning solvent or for chromatography). Isomers Uses In industry, hexanes are used in the formulation of glues for shoes, leather products, and roofing. They are also used to extract cooking oils (such as canola oil or soy oil) from seeds, for cleansi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Engine Knocking
In spark ignition internal combustion engines, knocking (also knock, detonation, spark knock, pinging or pinking) occurs when combustion of some of the air/fuel mixture in the cylinder does not result from propagation of the flame front ignited by the spark plug, but one or more pockets of air/fuel mixture explode outside the envelope of the normal combustion front. The fuel-air charge is meant to be ignited by the spark plug only, and at a precise point in the piston's stroke. Knock occurs when the peak of the combustion process no longer occurs at the optimum moment for the four-stroke cycle. The shock wave creates the characteristic metallic "pinging" sound, and cylinder pressure increases dramatically. Effects of engine knocking range from inconsequential to completely destructive. Knocking should not be confused with pre-ignition—they are two separate events. However, pre-ignition can be followed by knocking. The phenomenon of detonation was described in November 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Postal Service
The United States Postal Service (USPS), also known as the Post Office, U.S. Mail, or Postal Service, is an Independent agencies of the United States government, independent agency of the executive branch of the Federal government of the United States, United States federal government responsible for providing mail, postal service in the U.S., including its insular areas and Compact of Free Association, associated states. It is one of the few government agencies Postal Clause, explicitly authorized by the U.S. Constitution. The USPS, as of 2021, has 516,636 career employees and 136,531 non-career employees. The USPS traces its roots to 1775 during the Second Continental Congress, when Benjamin Franklin was appointed the first United States Postmaster General, postmaster general; he also served a similar position for the colonies of the Kingdom of Great Britain. The United States Post Office Department, Post Office Department was created in 1792 with the passage of the Postal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isomer
In chemistry, isomers are molecules or polyatomic ions with identical molecular formulae – that is, same number of atoms of each element – but distinct arrangements of atoms in space. Isomerism is existence or possibility of isomers. Isomers do not necessarily share similar chemical or physical properties. Two main forms of isomerism are structural or constitutional isomerism, in which '' bonds'' between the atoms differ; and stereoisomerism or spatial isomerism, in which the bonds are the same but the ''relative positions'' of the atoms differ. Isomeric relationships form a hierarchy. Two chemicals might be the same constitutional isomer, but upon deeper analysis be stereoisomers of each other. Two molecules that are the same stereoisomer as each other might be in different conformational forms or be different isotopologues. The depth of analysis depends on the field of study or the chemical and physical properties of interest. The English word "isomer" () is a bac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crude Oil
Petroleum, also known as crude oil, or simply oil, is a naturally occurring yellowish-black liquid mixture of mainly hydrocarbons, and is found in geological formations. The name ''petroleum'' covers both naturally occurring unprocessed crude oil and petroleum products that consist of refined crude oil. A fossil fuel, petroleum is formed when large quantities of dead organisms, mostly zooplankton and algae, are buried underneath sedimentary rock and subjected to both prolonged heat and pressure. Petroleum is primarily recovered by oil drilling. Drilling is carried out after studies of structural geology, sedimentary basin analysis, and reservoir characterisation. Recent developments in technologies have also led to exploitation of other unconventional reserves such as oil sands and oil shale. Once extracted, oil is refined and separated, most easily by distillation, into innumerable products for direct use or use in manufacturing. Products include fuels such as gaso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pittosporum Resiniferum
''Pittosporum resiniferum'', the resin cheesewood or petroleum nut, is a tree that grows in the Philippines and Malaysia, particularly in the wilderness surrounding the Mayon Volcano and in the Cordillera Administrative Region, Cordillera of the Philippines and Mount Kinabalu of Sabah, Malaysia. The petroleum nut derives its name from the resemblance of the fruit's odor to petroleum-based fuels. The fruits of the tree burn brightly when ignited, and can be used for illumination as torches or candles. Its fruit is also highly suitable for use in producing biofuel. This use has been encouraged by the Philippines Department of Agrarian Reform and the Philippine Coconut Authority. In the Philippine Cordilleras petroleum nut is locally known as apisang, abkel, abkol and da-il, is found among other trees like oak and other mossy forest species. It can also grow well with pine trees. The oil obtained from the fruit contains a dihydroterpene(C10H18) and also considerable quantities of no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkane
In organic chemistry Organic chemistry is a subdiscipline within chemistry involving the science, scientific study of the structure, properties, and reactions of organic compounds and organic materials, i.e., matter in its various forms that contain carbon atoms.Clay ..., an alkane, or paraffin (a historical trivial name that also has other meanings), is an acyclic saturated hydrocarbon. In other words, an alkane consists of hydrogen and carbon atoms arranged in a tree structure in which all the carbon–carbon bonds are single. Alkanes have the general chemical formula . The alkanes range in complexity from the simplest case of methane (), where ''n'' = 1 (sometimes called the parent molecule), to arbitrarily large and complex molecules, like Higher alkanes#Nonatetracontane to tetrapentacontane, pentacontane () or 6-ethyl-2-methyl-5-(1-methylethyl) octane, an isomer of tetradecane (). The International Union of Pure and Applied Chemistry (IUPAC) defines ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resin
In polymer chemistry and materials science, resin is a solid or highly viscous substance of plant or synthetic origin that is typically convertible into polymers. Resins are usually mixtures of organic compounds. This article focuses on naturally occurring resins. Plants secrete resins for their protective benefits in response to injury. The resin protects the plant from insects and pathogens. Resins confound a wide range of herbivores, insects, and pathogens, while the volatile phenolic compounds may attract benefactors such as parasitoids or predators of the herbivores that attack the plant. Composition Most plant resins are composed of terpenes. Specific components are alpha-pinene, beta-pinene, delta-3 carene, and sabinene, the monocyclic terpenes limonene and terpinolene, and smaller amounts of the tricyclic sesquiterpenes, longifolene, caryophyllene, and delta-cadinene. Some resins also contain a high proportion of resin acids. Rosins on the other hand ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Octane
Octane is a hydrocarbon and an alkane with the chemical formula , and the condensed structural formula . Octane has many structural isomers that differ by the amount and location of branching in the carbon chain. One of these isomers, 2,2,4-trimethylpentane (commonly called iso-octane) is used as one of the standard values in the octane rating scale. Octane is a component of gasoline (petrol). As with all low-molecular-weight hydrocarbons, octane is volatile and very flammable. Use of the term in gasoline "Octane" is colloquially used as a short form of "octane rating," particularly in the expression "high octane". "Octane rating" is an index of a fuel's ability to resist engine knock in engines having different compression ratios, which is a characteristic of octane's branched-chain isomers, especially iso-octane. The octane rating of gasoline is not directly related to the power output of an engine. Using gasoline of a higher octane than an engine is designed for cannot inc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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